Heat treatment process for knuckle bearing

Abstract

The invention discloses a heat treatment process for a knuckle bearing. The heat treatment process is characterized by comprising the following steps that (1) material selection of a part is conducted, and W18Cr4V is selected; (3) preheating treatment is conducted; (4) quenching treatment is conducted, and (5) tempering treatment is conducted. According to the heat treatment process for the knuckle bearing, preheating is conducted at first, so that large heat stress is avoided, and about 30% of residual austenite which is not converted into martensite is still reserved in the internal structure after quenching; and the process parameters of all stages are strictly controlled, procedures are remarkably reduced, the process is simple, operation is convenient, and energy consumption is low.

Description

technical field [0001] The invention belongs to the field of heat treatment technology, in particular to a joint bearing heat treatment technology. Background technique [0002] In the prior art, a joint bearing is made of GCr15 steel, which is a kind of high-carbon chromium bearing steel with less alloy content, good performance and the most widely used. H-class to C-class bearing sleeves with a diameter of 250mm are widely used in high-speed rotating and high-load mechanical parts and components, so they must have high strength, high elastic limit and high wear resistance. For ball bearing steel, the internal structure is flaky pearlite and reticular cementite. This kind of structure has high hardness, is difficult to machine, and is easy to wear the cutting tool. At the same time, due to the existence of reticular cementite, the steel The internal composition is not uniform, so that it will cause a large structural stress during quenching, which is easy to cause deformat...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, a joint bearing is made of GCr15 steel, which is a kind of high-carbon chromium bearing steel with less alloy content, good performance and the most widely used. H-class to C-class bearing sleeves with a diameter of 250mm are widely used in high-speed rotating and high-load mechanical parts and components, so they must have high strength, high elastic limit and high wear resistance. For ball bearing steel, the internal structure is flaky pearlite and reticular cementite. This kind of structure has high hardness, is difficult to machine, and is easy to wear the cutting tool. At the same time, due to the existence of reticular cementite, the steel The internal composition is not uniform, so that it will cause a large structural stress during quenching, which is easy to cause deformation or cracking of the parts. In order to improve this structure, in addition to using normalizing treatment to eliminate the reticulated cementitious body, the use of spheroidizing annealing is Necessary. However, the traditional conventional spheroidizing annealing process has a long period, high energy consumption, low efficiency, and uneven carbide size distribution, which affects its application